1. Technical Field
The present invention relates in general to grid environments and in particular to managing application operation in a grid environment. Still more particularly, the present invention relates to maintaining application operation within a suboptimal grid environment by reconfiguring the application according to an application profile which expresses the operational requirements of an application in a grid environment.
2. Description of the Related Art
Ever since the first connection was made between two computer systems, new ways of transferring data, resources, and other information between two computer systems via a connection continue to develop. In a typical network architecture, when two computer systems are exchanging data via a connection, one of the computer systems is considered a client sending requests and the other is considered a server processing the requests and returning results. In an effort to increase the speed at which requests are handled, server systems continue to expand in size and speed. Further, in an effort to handle peak periods when multiple requests are arriving every second, server systems are often joined together as a group and requests are distributed among the grouped servers. Multiple methods of grouping servers have developed such as clustering, multi-system shared data (sysplex) environments, and enterprise systems. With a cluster of servers, one server is typically designated to manage distribution of incoming requests and outgoing responses. The other servers typically operate in parallel to handle the distributed requests from clients. Thus, one of multiple servers in a cluster may service a client request without the client detecting that a cluster of servers is processing the request.
Typically, servers or groups of servers operate on a particular network platform, such as Unix or some variation of Unix, and provide a hosting environment for running applications. Each network platform may provide functions ranging from database integration, clustering services, and security to workload management and problem determination. Each network platform typically offers different implementations, semantic behaviors, and application programming interfaces (APIs).
Merely grouping servers together to expand processing power, however, is a limited method of improving efficiency of response times in a network. Thus, increasingly, within a company network, rather than just grouping servers, servers and groups of server systems are organized as distributed resources. There is an increased effort to collaborate, share data, share cycles, and improve other modes of interaction among servers within a company network and outside the company network. Further, there is an increased effort to outsource nonessential elements from one company network to that of a service provider network. Moreover, there is a movement to coordinate resource sharing between resources that are not subject to the same management system, but still address issues of security, policy, payment, and membership. For example, resources on an individual's desktop are not typically subject to the same management system as resources of a company server cluster. Even different administrative groups within a company network may implement distinct management systems.
The problems with decentralizing the resources available from servers and other computing systems operating on different network platforms, located in different regions, with different security protocols and each controlled by a different management system, have led to the development of Grid technologies using open standards for operating a grid environment. Grid environments support the sharing and coordinated use of diverse resources in dynamic, distributed, virtual organizations. A virtual organization is created within a grid environment when a selection of resources from geographically distributed systems operated by different organizations with differing policies and management systems is organized to handle a job request.
An important attribute of a grid environment that distinguishes a grid environment from merely that of another management system is quality of service maintained across multiple diverse sets of resources. A grid environment preferably does more than just provide resources; a grid environment provides resources with a particular level of service including response time, throughput, availability, security, and the co-allocation of multiple resource types to meet complex user demands. In an effort to provide quality of service, however, the issue in a grid environment is how to meet performance requirements when the reality of network systems is that optimal performance is not always available.
First, a reality of network systems is that applications are typically written to execute on specific platforms with specific operational requirements. In particular, the operational requirements of applications are often specified from measurements run under optimal conditions on the particular platform. Thus, application behavior differs extensively when run on a non-native platform or resources. Therefore, when multiple heterogeneous systems are linked together in a grid environment, there is an issue of how to maintain quality of service when applications are executing on non-native platforms. In particular, there is currently no means to express each application's operational requirements for execution in a grid environment where the available resources with which to execute a job may change rapidly over an interval of time.
Further a reality of network systems, is that applications are typically written where modules of the application are written to execute on specific platforms with relatively static resource pools. Thus, when an application written for a relatively static resource pool is encounters suboptimal operating conditions, the entire application shuts down.
Moreover, within a grid environment, applications are just one level of the functionality of a grid architecture. In addition to the application level, multiple levels and types of services are available to be implemented by an application. The same issues for maintaining quality of service for applications apply when these service layers run on multiple heterogeneous platforms within a grid environment.
Therefore, in view of the foregoing, there is a need for a method, system, and program to manage the software layers of functionality within a grid environment and in particular, to change an application or service behavior to maintain quality of service. Thus, there is a need for a method, system, and program to express an application or service's operational requirements for use in a grid environment, such that when suboptimal performance is detected in the grid environment, the operational behavior of an application or service can be reconfigured based on the operational requirements of the application.